Electrical connecting device



Nov. 9 1926.

P. UTNE ELECTRICAL CONNECTING DEVICE Filed Dec. 51, 1924 Fig.2.

INVENTOR: EM, M,

BY ATTORNEY Patented Nov. 9, 1926.

UNITED STATES I 1,606,457 PATENT OFFICE.

PER UTNE, OF EDGEWOOD BOROUGH, PENNSYLVANIA: ASSIGNOR TO THE UNION SWITCH & SIGNAL COMPANY, OF SWISSVALE, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

IE2Il'.|ECTRICAIIZI CONNECTING DEVICE.

Application filed December 31, 1924. Serial No. 759,169.

My invention relates to electrical connecting devices, and particularly to devices for connecting the elements of a multiple-electrode electron tube with external circuits.

I will describe one form of devices embodying my invention, and will then point out the novel features thereof in claims.

In the accompanying drawing, Fig. 1 is a top plan view of one form of device embodying my invention. Fig. 2 is a sectional view along the line II-II of Fig. 1. Fig. 3 is a detail view showing in top plan one of the contact finger assemblies for the device illustrated in Figs. 1 and 2. Fig. 4 is a view showing in side elevation, the contact finger assembly shown in Fig. 3.

Similar reference characters refer to similar parts in each of the several views.

Referring first to Figs. 1 and 2, the device comprises a body A of suitable insulating material such as a molded condensation phenol product. This body A is constructed with a bottom portion A here illustrated as cylindrical in shape, and a centrally located neck portion A provided with a standard bayonet socket B of the usual form having the customary slot 1 with a notch 10 at the end of the slot to form a lock. The neck portion A and the bottom portion A are connected by an annular shoulder A shown inclined to save space and to make the terminals more accessible. The socket B is particularly adapted to receive multiple contact bayonet bases such as are commonly provided on electron tubes. Tubes of this character usually have four downwardly projecting spaced studs 2 on the under side of the base as indicated in dotted lines in Figs. 1 and 2.

It is desirable to provide means for securing good electrical contact with each of these studs separately for the purpose, of connection with external circuits. It is also desirable that when the base 0 is inserted in the socket C and locked, pressure should be constantly applied on the under side of the base to prevent vibration of the tube D.

I therefore provide the shoulder A with "a plurality of apertures 3 each adapted to receive a supporting block 4. Each block comprises a threaded shank 4 and two spaced heads 5 and 5 The block is centrally drilled and threaded internally for a purpose which will hereinafter appear.

The shank 4 of each block 4 passes through the corresponding aperture 3 and is secured in place by a nut 9 threaded on the outside of the shank at the upper end of the shank. A contact finger G is attached to the lower end of each block 4. Referring now also to Figs. 3 and 4, each finger G comprises a length of wire 6 of resilient conducting material such as phosphor bronze. One end .of this wire is formed into an eye which is clamped between the two heads 5 and 5 of the associated block 4. The free end of each finger G'is bent to suitable shape, such as into a small loop 6. proportioned and disposed that the free ends of all the fingers incline upwardly toward the center of socket B. The spacing of the members is such that when a base 0 is insertedin the socket the loop 6 or each The fingers are so finger G engages the lower side of the base.

To lock the base in place, then, pressure must be exerted which deflects the fingers G downward as seen in Fig. 2. As the base is inserted and turned in the socket to lock the base in place each of the studs Zthereon makes a wiping side contact with one of the fingers G, thus deflecting the finger outwardly from the center of the base. In F 'igs. 3 and4 the full lines illustrate the shape of the finger G under normal conditions, and the dotted lines 7 indicate the shape of the finger in the deflection position assumed by the fingers when a base is locked in the socket.

Connections may be made from external circuits to each finger G, and hence to the associated stud.2, by means of a screw 8 threaded into the top of the corresponding block 4.

The contact stud ordinarily employed in electron tube bases are tubular, In common practice the lead wires from the tube elements are severally inserted in the various tubular studs and cut off flush with the end of the stud. Contact is then made by soldering the lead wire to the end of the tubular stud. Each stud is'thereby capped with a tip of solder.

In at least. one form of electron socket hitherto suggested, the contact springs in electrical connection is made through the solder tip. Experience has shown that such contact is unreliable in practice because of the wear on the soft solder and also because of the oxidation or corrosion of the solder.

Sockets have been suggested prior to my present invention in which the contact springs were arranged to bear against the sides of the studs, but in no such suggested socket has there been any provision for urging the base of the tube out of the socket to secure the lock between the pin on the electron tube base and the notch 10 in the socket.

The material of which the studs are construeted is less easily corroded than the solder and hence the side contact is more reliable than the solder tip contact. Furthermore, in my invention, each time the tube is inserted or removed from the socket, the 1 contact springs wipe against the studs and thus keep the contact surfaces clean and hence keep the contact resistance at a minimum value.

In addition to this advantage it will be evident that in my invention, when the base is inserted in the socket each finger G exerts pressure not only against the side of the corresponding stud, but also against the bottom of the base, thereby holding the base rigidly in position, preventing the tube from jarring out of the socket, and eliminatin the so called microphone action resulting rom mechanical vibration of the tube elements.

Devices embodying my invention therefore provide a novel arrangement of contact springs which combine the electrical superiority of the side contact with the mechanical advantage of the end contact.

Although I have. herein shown and described only one form of device embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

l. A socket for co-operation with a bayonet base having a plurality of spaced studs outstanding from the bottom thereof, said socket comprising a plurality of contact fingers arranged to be deflected by engagement with the bottom of said base when the base is inserted in the socket, said fingers being also arranged so as to be further deflected by engaging with the sides of the several said studs when the base is locked in the socket.

2. A socket for co-operation with a bayonet base having a plurality of spaced studs outstanding from the bottom thereof, said socket comprising a plurality of contact fingers arranged to urge said base out of said socket by engagement with the under side of the base, and the fingers being so disposed as to establish wiping contact with thesides of the several studs of the base when such base is locked in the socket.

3. In combination, a member of insulating material having attached thereto a bayonet socket adapted to receive, a bayonet base provided with a stud projecting downwardly from its under side, and a resilient finger attached to said insulating member and arranged to engage the under surface of said base to prevent vibration of the base and also to wipe against said stud when the base is locked in the socket.

4. In combination, a member of insulating material having attached thereto a bayonet socket adapted to receive a bayonet base provided with a stud projecting downwardly from its under side, and a resilient finger having one end secured to said member and having the free end formed to engage the bottom of said base and also to engage the side of said stud when the base is locked in said socket.

5. In combination, a member of insulating material having attached thereto a bayonet socket adapted to receive a bayonet base provided with a plurality of downwardly projecting spaced studs, and a plurality of spaced fingers each having one end fixed to said member and so arranged that the free ends of said fingers engage the under side of said base and severally make electrical contact with sides of said studs when the base is locked in the socket.

6. In combination, a member of insulating material having a vertically disposed bayonet socket for co-operation with a bayonet base provided with a plurality of downwardly projecting spaced studs, and a plurality of spaced contact fingers each comprising a length of resilient wire having one end rigidly attached to said member and the other end formed and extending upwardly and toward the center of said socket so that the ends of all said fingers engage the under side of said base and severally engage the sides of said studs when the base is inserted and locked in the socket.

In testimony whereof I afiix my signature.

PER UTNE. 

